In the 20th century, society was either ignorant of, or ignored, the consequences of bad water management. The goal was economic development at all costs. Over the past few decades, we’ve learned about the ecological and social implications of the misuse of water, and some efforts have been made to protect natural ecosystems, restore a modicum of flows, bring local communities into the discussion about water policy and infrastructure. These are steps in the right direction.
But sometimes our failures have been monumental — and uncorrected.
Perhaps the best, or worst, example, is the complete destruction of the Aral Sea. Once one of the four largest lakes in the world by surface area, fed by the Amu Darya and Syr Darya rivers, it has now been destroyed by the complete diversion of inflows to grow crops — largely cotton — in the arid regions of Uzbekistan (with parts of the watershed of the Sea in Tajikistan, Turkmenistan, Kyrgyzstan and Kazakhstan).
All 24 species of fish endemic to the Aral Sea are now extinct. Dust storms spread respiratory diseases. And the local climate has been altered.
Here is an animated gif showing the disappearance of the sea between 2000 and just last month: August 2014 (data/satellite images courtesy of NASA).